Apobaetis, Day, 1955

De Lima, Claudia R. T., Cruz, Paulo Vilela & Hamada, Neusa, 2024, Five new species of Apobaetis Day (Ephemeroptera: Baetidae) and updated key to nymphs, Zootaxa 5397 (1), pp. 91-115 : 111-112

Key to the species of Apobaetis

1. Labial palp segment II with rounded distomedial projection ( Fig. 4G in De Lima et al. 2022)......................... 2

1’. Labial palp segment II with triangular distomedial projection ( Fig. 2G )........................................... 6

2. Dorsal surface of labrum with robust and pointed medial setae near distal margin ( Fig. 2A in Cruz et al. 2020a)............................................................................ A. biancae Cruz, Boldrini & Hamada, 2020

2’. Dorsal surface of labrum without robust and pointed medial setae near distal margin ( Fig. 1A in Cruz et al. 2020a)....... 3

3 (2’). Subtriangular process of left mandible containing a prominent spur on distal margin ( Fig. 4C in De Lima et al. 2022).................................................................. A. irai De Lima, Massariol, Cruz & Hamada, 2022 .

3’ (2’). Subtriangular process of left mandible without a prominent spur on distal margin ( Fig. 1B in Cruz et al. 2020a).......... 4

4 (3’). Posterior margin of abdominal terga IV without spines ( Fig. 11 in Cruz & De-Souza 2014); labial palp segment III rectangular ( Fig. 6 in Cruz & De-Souza 2014).......................................... .. A. kethepiali Cruz & De-Souza, 2014

4’ (3’). Posterior margin of abdominal terga IV with spines ( Fig. 3C ); labial palp segment III triangular ( Fig. 2G )................5

5 (4’). Glossa distally rounded ( Fig. 1F in Cruz et al. 2020a)................................... A. lakota McCafferty, 2000

5’ (4’). Glossa distally pointed ( Fig. 3F in Cruz et al. 2020a)....................... A. jacobusi Cruz, Boldrini & Hamada, 2020

6 (1’). Distal margin of labrum with medial spine-like setae ( Fig. 13A ); labial palp segment III triangular ( Fig. 13G )............7

6’ (1’). Distal margin of labrum with medial blunt setae ( Fig. 11A ); labial palp segment III rectangular or subtriangular ( Fig. 2G ; 11G )................................................................................................... 11

7 (6). Subtriangular process in left mandible with three short spine-like setae on base ( Fig. 10D and E in De Lima et al. 2023) ................................................................................................. A. luanae

7’ (6). Subtriangular process in left mandible without spine-like setae on base ( Fig. 2C ) ................................... 8

8 (7’). Posterior margin of abdominal terga IV with minute and rounded spines (Fig. 28 in Nieto 2006)............. A. kallawaya

8’ (7’). Posterior margin of abdominal terga IV with prominent, pointed or rounded spines ( Fig. 3C ; 12C ) ...................... 9

9 (8’). Distal margin of labrum without emargination (presence of medial lobe) (Fig. 19 in Nieto 2006) ........ A. niger Nieto, 2006

9’ (8’). Distal margin of labrum with medial emargination ( Fig. 6a and 6b in Nieto 2006)................................. 10

10 (9). Posterior surface of femur with minute and blunt setae near dorsal margin ( Fig. 14A and B )........... A. danielae sp. nov.

10’ (9). Posterior surface of femur without setae near dorsal margin ( Fig. 13 in Nieto 2006) ............... A. insolitus Nieto, 2006

11 (6’). Labial palp with subtriangular segment III ( Fig. 11G )....................................................... 12

11’ (6’). Labial palp with rectangular segment III ( Fig. 2G )......................................................... 13

12 (11). Tarsal claws 1.1× longer than tarsus, without row of denticles (Fig. 17 in Cruz et al. 2011).............................................................................................. A. hamadae Cruz, Boldrini & Salles, 2011

12’ (11). Tarsal claws 0.6–0.7× length of tarsus, with two row of minute denticles ( Fig. 12B ).................. A. nisiae sp. nov.

13 (11’). Tarsal claws I, II and III with two rows of denticles ( Fig. 8C in De Lima et al. 2023).................... A. jaquelinae

13’ (11’). Tarsal claws I, II and III without two row of denticles ( Fig. 3A )............................................. 14

14 (13’). Maxillary palp with apex of segment II with constriction (Fig. 19 in Cruz & De-Souza 2014)....................... 15

14’ (13’). Maxillary palp with apex of segment II without constriction ( Fig. 2F )......................................... 16

15 (14). Inner margin of glossa with setae ( Fig. 2F in Cruz 2020)................................. .. A. etowah (Traver, 1935)

15’ (14). Inner margin of glossa without setae (Fig. 21 in Cruz & De-Souza 2014).............. A. pucupi Cruz & De-Souza, 2014

16 (14’). Posterior margin of abdominal terga IV with triangular rounded spines ( Fig. 7C in Cruz 2020).......................................................................................... A. signifer Lugo-Ortiz & McCafferty, 1997

16’ (14’). Posterior margin of abdominal terga IV with triangular pointed spines ( Fig. 3C )................................ 17

17 (15’). Posterolateral extension of paraproct without spines ( Fig. 6E )............................................... 18

17’ (15’). Posterolateral extension of paraproct with spines ( Fig. 3D in Cruz 2020) ....................................... 19

18 (17). Paracercus with lateral spines in alternate segments ( Fig. 6G )................................... A. trivellae sp. nov.

18’ (17). Paracercus with lateral spines in all segments ( Fig. 5G in De Lima et al. 2023)........................ A. pasternakae

19 (17’). Glossa longer than paraglossa ( Fig. 8G ); distomedial projection of segment II 1.2× longer than segment III ( Fig. 8G )....................................................................................... A. dalcolmoae sp. nov.

19’ (17’). Glossa subequal to paraglossa ( Fig. 2G ); distomedial projection of segment II never exceeding segment III ( Fig. 2G )....20

20 (19’). Maxillary palp 2.3× length to galea-lacinia, with prominent palpifer ( Fig. 2F )..................... A. sabinoae sp. nov.

20’ (19’). Maxillary palp 1.5× length to galea-lacinia, without prominent palpifer ( Fig. 4E )........................... A. fiuzai

Figures

FIGURE 1. Apobaetis sabinoae sp. nov., habitus of nymph. A. male nymph (d.v.). B. male nymph (l.v.). C. male nymph (v.v.).

FIGURE 2. Apobaetis sabinoae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of blunt medial setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 3. Apobaetis sabinoae sp. nov. Holotype, thorax and abdomen of nymph. A. foreleg (femur on anterior surface). B. detail of setae on anterior surface of forefemur. C. posterior margin of tergum IV. D. gill. E. cercus. F. paracercus. G. paraproct.

FIGURE 4. Apobaetis trivellae sp. nov., habitus of nymph. A. male nymph (d.v.). B. male nymph (l.v.). C. male nymph (v.v.).

FIGURE 5. Apobaetis trivellae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of blunt medial setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 6. Apobaetis trivellae sp. nov. Holotype, thorax and abdomen of nymph. A. foreleg (femur on anterior surface). B. detail of setae on anterior surface of forefemur, setae on posterior surface dotted. C. posterior margin of tergum IV. D. gill. E. paraproct. cercus. F. cercus. G. paracercus.

FIGURE 7. Apobaetis dalcolmoae sp. nov., habitus of nymph. A. female nymph (d.v.). B. female nymph (l.v.). C. female nymph (v.v.).

FIGURE 8. Apobaetis dalcolmoae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of blunt medial setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 10. Apobaetis nisiae sp. nov., habitus of nymph. A. female nymph (d.v.). B. female nymph (v.v.). C. detail of abdomen of nymph (d.v.).

FIGURE 11. Apobaetis nisiae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of blunt medial setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 12. Apobaetis nisiae sp. nov. Holotype, thorax and abdomen of nymph. A. foreleg (femur on anterior surface). B. detail of two row of denticles on tarsal claw. C. posterior margin of tergum IV. D. gill. E. paraproct F. cercus. G. paracercus.

FIGURE 13. Apobaetis danielae sp. nov. Holotype, mouthparts of nymph. A. labrum (left d.v., right v.v). B. detail of medial bifid spine-like setae near to distal margin on dorsal surface of labrum. C. left mandible. D. right mandible. E. hypopharynx. F. maxilla. G. labium (left d.v., right v.v.). H. detail of setae on apex of glossa (d.v.).

FIGURE 14. Apobaetis danielae sp. nov. Holotype, thorax and abdomen of nymph. A. foreleg (femur on anterior surface), setae on posterior surface dotted. B. detail of setae on posterior surface of forefemur. C. detail of two row of denticles on tarsal claw. D. paraproct. E. cercus. F. paracercus.